A Muay Thai fighter took a brutal elbow to the face during a fight in Thailand this week -- requiring emergency surgery ... but don't worry, HE'S OKAY!!!!

Pro fighter Jonny Betts was at the Patong Stadium in Thailand on Monday night -- when his friend, "Jeremy," suffered a skull fracture in the ring.

Betts says Jeremy was out of the hospital in just a few days after undergoing a procedure to "fix up the fracture with a titanium plate."

"No brain injury and he was never dizzy."

Get well soon, man.